Boechera paupercula |
Boechera schistacea |
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boechera paupercula, littleleaf rockcress, small-flower rock-cress, tiny suncress |
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Habit | Perennials; long-lived; (cespitose); sexual; caudex often woody. | Perennials; long-lived; sexual; caudex woody. |
Stems | usually 1 per caudex branch, arising from center of rosette near ground surface, 0.3–1.5 dm, densely pubescent proximally, trichomes simple and short-stalked, 2–4-rayed, (0.07–)0.1–0.2 mm, glabrous or sparsely pubescent distally. |
usually 2–5 per caudex branch, arising from margin of rosette, elevated above ground surface on woody base, 0.8–2.5(–4) dm, glabrous throughout. |
Basal leaves | blade linear-oblanceolate, 1–3(–5) mm wide, margins entire, ciliate proximally, trichomes to 0.4 mm, surfaces densely pubescent, trichomes short-stalked, 2–6-rayed, (0.07–)0.1–0.2 mm. |
blade linear to narrowly oblanceolate, 1.2–2.5 mm wide, margins entire, ciliate proximally, trichomes (simple), 0.3–0.7 mm, surfaces glabrous or sparsely pubescent, trichomes short-stalked, 2- or 3-rayed, 0.2–0.5 mm. |
Cauline leaves | 2–6, rarely concealing stem; blade auricles 0 (or 0.2–1.5) mm, surfaces of distalmost leaves glabrous. |
2–5(–9), not concealing stem; blade auricles 0.2–0.5 mm, surfaces of distalmost leaves glabrous. |
Racemes | 3–8-flowered, unbranched. |
5–12-flowered, usually unbranched. |
Flowers | erect at anthesis; sepals glabrous or sparsely pubescent; petals lavender to purplish, 4–6(–7) × 1–2 mm, glabrous; pollen ellipsoid. |
divaricate-ascending at anthesis; sepals glabrous; petals white to lavender, 4–6 × 1–1.5 mm, glabrous; pollen ellipsoid. |
Fruiting pedicels | erect, straight, 3–9 mm, glabrous or sparsely pubescent. |
reflexed, curved, 5–9 mm, glabrous. |
Fruits | erect, appressed to rachis, not secund, straight, edges parallel, 2.5–5.5 cm × 1.3–1.7(–2) mm; valves glabrous; ovules 24–40 per ovary; style 0.2–1 mm. |
pendent, not appressed to rachis, not secund, straight, edges parallel, 1.8–4.5 cm × 1.5–2 mm; valves glabrous; ovules 24–36 per ovary; style 0.2–0.5 mm. |
Seeds | usually uniseriate, rarely sub-biseriate, 1.5–2(–2.5) × 1–1.4 mm; wing continuous, 0.3–1 mm wide. |
uniseriate, 0.9–1.2 × 0.7–0.9 mm; not winged. |
2n | = 14. |
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Boechera paupercula |
Boechera schistacea |
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Phenology | Flowering Jun–Aug. | Flowering May–Jul. |
Habitat | Rock outcrops, talus slopes, gravelly soil in alpine and subalpine habitats | Rocky slopes and gravelly soil in sagebrush, open conifer forests, and subalpine meadows |
Elevation | 2400-3400 m (7900-11200 ft) | 2400-3200 m (7900-10500 ft) |
Distribution |
CA; ID; OR; WA; WY
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NV; UT |
Discussion | Boechera paupercula is usually subsumed under Arabis (Boechera) lyallii but is amply distinct (see M. D. Windham and I. A. Al-Shehbaz 2006 for detailed comparison). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boechera schistacea is a sexual diploid that appears to intergrade with B. pendulina where their geographic ranges overlap in southwestern Utah. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 394. | FNA vol. 7, p. 404. |
Parent taxa | Brassicaceae > tribe Boechereae > Boechera | Brassicaceae > tribe Boechereae > Boechera |
Sibling taxa | ||
Synonyms | Arabis paupercula, Arabis lyallii var. nubigena, Arabis microphylla var. nubigena, Arabis nubigena | Arabis schistacea |
Name authority | (Greene) Windham & Al-Shehbaz: Harvard Pap. Bot. 11: 75. (2006) | (Rollins) Dorn: Brittonia 55: 3. (2003) |
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